--WALKER WOULDN'T RULE OUT RE-INVASION OF IRAQ: Wisconsin Gov. Scott Walker says he wouldn't rule out a full-blown re-invasion of Iraq if he were to become the next commander-in-chief. The likely Republican presidential candidate and early frontrunner in several polls said he would consider a re-invasion if it were deemed necessary to protect American national security at home and abroad. "It would not be limited to anything out there," Walker told ABC's JONATHAN KARL in an exclusive interview with for "This Week." "Once we start saying how far we're willing to go or how many troops we're willing to invest, we send a horrible message, particularly to foes in the Middle East who are willing to wait us out." http://abcn.ws/1QfEWlO

--CALLS POSSIBILITY OF TAKING ONLINE COURSES TO FINISH DEGREE IN WH 'INTERESTING.’: Walker told ABC News that the possibility of taking online courses to finish his college degree -- if he were to win the presidential election and found himself at 1600 Pennsylvania Avenue in early 2017 -- is "interesting." "I've got two sons who very, very well, before the next election, at least one of them, may have his degree and the other would be just a year out," Walker told ABC's JONATHAN KARL. "Part of it was I wanted to make sure they went through and got what they needed," he said. ABC's BENJAMIN BELL has more: http://abcn.ws/1KiO7gj

--WALKER DEFENDS TAX DOLLARS, POSSIBLE RATE HIKE FOR NEW SPORTS ARENA: Walker also defended the approval of $250 million in state taxpayer funds to help build a new arena for the Milwaukee Bucks of the NBA. The project is a "good deal" for the state economy, he told ABC's JONATHAN KARL on "This Week," and he insisted that it is "not a new tax.” "We would lose $419 million over the next 20 years if we did nothing, if we said, go on, move somewhere else, which the NBA said they would do," Walker continued. ABC's JORDYN PHELPS reports that conservative advocacy groups, including the Koch brothers' Americans for Prosperity, have blasted the proposal as bad for taxpayers, but Walker brushed off the criticism. "All across the nation when they do projects like this," Walker said. "It's a good deal." http://abcn.ws/1doMroq

--ANALYSIS -- ABC’s RICK KLEIN: Straw polls don’t count for anything, and second place is, well, second place. But how many of these before it will become something? Hillary Clinton captured 49 percent of the vote at the Wisconsin Democratic Party’s convention over the weekend, in a straw poll conducted by WisPolitics.com. The story, though, was second place: Bernie Sanders got 41 percent, just eight points behind Clinton and far ahead of his low-single-digits rivals. It’s the latest sign that Sanders is poised to inherit at least a solid portion of the Ready-for-Warren energy. And it speaks to a longstanding contention that if Clinton is vulnerable, it’s on her left. The labor-friendly progressives who dominate Wisconsin Democratic politics aren’t necessarily representative of the primary electorate, though Wisconsin was among the states that broke Clinton’s heart in the 2008 primaries. With recent events putting Clinton’s vulnerabilities on greater display, the possibility of at least one of her challengers getting a serious look is growing.

THE BUZZ

with ABC’s VERONICA STRACQUALURSI

5 STORIES YOU'LL CARE ABOUT IN POLITICS THIS WEEK. Admit it -- you were trying to figure out what zero percent is if we go metric. Or maybe you were busy watching someone taking the whole "running" thing too seriously. Don't sweat it and don't drive too fast on the way there -- we've got you covered while you're counting up the number of current Republican candidates for president. It's 10, and remarkably, that number might not change in the next week, but will grow soon enough. ABC's RICK KLEIN highlights the five stories the ABC News political team will be tracking in the week ahead. http://abcn.ws/1HTxu5Q

IOWA SEN. JONI ERNST SAYS SHE’S NO KINGMAKER, BUT KEEPS VP DOOR OPEN. Iowa Sen. Joni Ernst declined to embrace the title of "kingmaker" even as seven potential Republican presidential candidates flocked to her home state to attend her inaugural "Roast and Ride" extravaganza this weekend. The freshman Republican senator simply called herself "an advocate for Iowa" while speaking with ABC's JONATHAN KARL. Republican hopefuls including former Texas Gov. Rick Perry and Florida Sen. Marco Rubio were among those at her event Saturday, ABC's BENJAMIN BELL notes. Ernst gained attention during her run for Senate with an advertisement in which she outlined having castrated hogs while growing up on a farm. Earlier this year, the U.S. military veteran was selected to give the GOP’s response to President Obama’s State of the Union address. Ernst delivered the response without issue and she did it wearing camo-heels. http://abcn.ws/1Hf63HQ

ERNST: 'I RIDE A HOG' The freshman Republican Iowa senator gives us the lowdown on her Harley. WATCH: http://abcn.ws/1Kiz6er

TODAY ON THE TRAIL with ABC’s CHRIS GOOD: Bill and Chelsea Clinton will be in Denver to host the fifth CGI America conference, being held June 8-10. Rick Perry will be in South Carolina, where he'll hold an event with former Navy SEAL and “Lone Survivor” author Marcus Luttrell at the SC Military Museum in Columbia at 10 am ET. They'll hold a veterans' town-hall at the USS Yorktown in Mt. Pleasant at 6 pm ET. Rick Santorum will be in Iowa, where he'll visit Panora Telecom Solutions in Panora at 1 pm ET, Darrell's Place in Hamlin at 3 pm ET, and Sam's Sodas & Sandwiches in Carroll at 5 pm ET. He'll address the Crawford County GOP in Denison at 7 pm ET. Chris Christie will be in New Hampshire, where he'll hold a town-hall at The Village Trestle in Goffstown at 5 pm ET. Later, he'll attend a house party in Bedford at 7:30 pm ET. Carly Fiorina will be in New Hampshire, where she will attend a house party in Londonderry at 7:10 pm ET.

IN CASE YOU MISSED IT

DID OBAMA GIVE IRAQI LEADER THE COLD SHOULDER AT G7 SUMMIT? A truly fascinating moment today at the G7 Summit when it appeared President Obama gave Iraqi Prime Minister the cold shoulder, ABC’s ARLETTE SAENZ notes. Whether it was intentional or not is unclear. At one point President Obama and other leaders sat down on a long wooden bench. President Obama was in deep conversation with Mario Renzi and Christine Lagarde. Then Iraqi Prime Minister Abadi walked up and sat down next to the president – but apparently, President Obama may not have noticed. Obama’s body was angled away from Abadi, but he never spoke to the leader as they sat side by side for nearly 30 seconds. The Iraqi prime minister eventually looked at his watch and his translator threw his hands up in the air. WATCH: http://abcn.ws/1BU1k8h